Cutoff knife for packaging machine



1970 D. D. ZIMMERMAN 3,524,301

CUTOFF KNIFE FOR PACKAGING MACHINE Filed Dec. 10, 1968 3 Sheets-Sheet l'I'HHIIIIIIQIHEIHIIIIIIIIHIIH.

Z6 JO FIG. v8 2 E INVENTOR. 5 ZAEk/M/ a z/mleem/v E BY 2 WM, m2: w

A TTOEA/EVS 1970 D. D; ZIMMERMAN 3,524,301

CUTOFF KNIFE FOR PACKAGING MACHINE Filed Dec. 10, 1968 3 Sheets-Sheet 2I NVEN'TOR.

ATTOZA/EVS PALZM/K/ P. Z/MMEZM4A/ v Aug. 18, 1970 D. D. ZIMMERMAN3,524,301

CUTOFF KNIFE FOR PACKAGING MACHINE Filed Dec. 10, 1968 3 SheetsSheet 5FIG. 5

I N VEN TOR.

United States Patent US. 01. s3 1s2 6 Claims ABSTRACT OF THE DISCLOSUREA packaging machine having an elongated cutoff knife housed within oneof a pair of oppositely disposed, rotatable sealing dies, and anactuating mechanism operative to intermittently move the knife through acontinuous length of wrapping material between spaced-apart articlesenclosed therein into a receiving slot on the other one of the sealingdies. The knife cuts through the wrapping material in a rapid, slicingmotion when the sealing dies are in engagement with opposite sides ofthe wrapping material during a crimping and sealing operation, a tripmember serving to initiate the actuation of the knife at the desiredtime.

BACKGROUND OF THE INVENTION Packaging machines of the type in whicharticles to be wrapped are entubed in a continuous, moving length ofwrapping material have conventionally employed rotary sealing andcut-off dies which operate to seal and sever the wrapping materialbetween adjacent articles. The use of rotary cutting dies which projectradially outwardly beyond the crimping and sealing dies in the mannershown in US. Pat. No. 2,546,721, is disadvantageous in that theprojecting cutting dies necessarily interfere with the substantiallysimultaneous sealing of the wrapper ends between the mating sealingdies. As the projecting cut-off dies rotate into contact with eachother, they tend to hold the sealing dies apart, thereby reducing thepressure contact of the sealing dies necessary to effect proper sealingof the wrapper web.

Also, the fixed mounting of the cutoff dies on the opposed sealing diessubstantially precludes the use of such combined sealing and cut-offdies in so-called strip packaging operations where a predeterminednumber of packaged articles are to be connected together by the wrappingWeb in a single strip. With the cutoff dies fixed to the ends of thesealing dies, there is no way that the cutting operation can beselectively controlled in such a way as to permit a predetermined numberof packaged articles to pass between the sealing dies before the web issevered.

The cutoff knife arrangement of this invention has been designed with aview towards overcoming the aforesaid difliculties associated with priorart packaging machines.

BRIEF SUMMARY OF THE INVENTION Having in mind the foregoing difiicultiesassociated with prior art packaging machines, I have developed a newmachine which is particularly characterized by a guillotine type ofcutoff knife which provides a sharp,

quick cutting action and which does not depend upon pressure for itsoperation. The cutoff knife is advantageously housed with a recess inone of the rotary sealing dies, and is movable therefrom into acomplementary opening or slot in the other one of the sealing dies toaccomplish the severing of the wrapping web. The knife is preferably inthe form of an elongated, sharp-edged blade which is moved through theWrapping material in a guillotine-like severing motion by an operatingmechanism when the crimping and sealing dies are in a predeterminedposition of alignment in engagement with the wrapping web.

A beneficial feature of my invention resides the mounting of the cutoffknife within a recess in one of the sealing dies in such a way that theknife cutting edge does not normally project outwardly beyond theperipheral surface of the sealing die. There is thus no outwardlyprojecting cutoff member to interfere with the pressure contact betweenthe mating sealing dies. This is especially important on a strippackaging operation wherein the wrapping web must be crimped and sealedbetween adjacent articles several times without severing the wrappingweb.

In order to actuate the knife-operating mechanism, I utilize a strike ortrip member which may take the form of a cam rotatably mounted on one ofthe sealing die shafts, but which is preferably a stationary membermounted on one of the spring-loaded bearing blocks within which theshaft supporting the sealing die holding the cutoff knife is rotatablysupported.

My invention is further advantageously characterized by an embodimentwherein the trip member for the knife-operating mechanism is movable inand out of its operating position by a control arrangement which shiftsthe trip member into position to actuate the cutoff knife in response tothe passage of a predetermined number of packaged articles between thesealing dies to facilitate a strip packaging operation.

These and other objects and advantages of my invention will becomereadily apparent as the following description is read in conjunctionwith the accompanying drawings wherein like reference numerals have beenused to designate like elements throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front, elevation view of apreferred embodiment of the packaging machine of this invention;

FIG. 2 is a side elevation view of the machine of FIG. 1;

FIG. 3 is a vertical section view taken along lines 3-3 of FIG. 1;

FIG. 4 is a partial end view taken along lines 4-4 of FIG. 1;

FIG. 5 is a fragmentary, rear elevation view of an alternative form ofthe cut-off mechanism of this invention;

FIG. 6 is a vertical section view taken along lines 66 of FIG. 5;

FIG. 7 is a vertical section view taken along lines 77 of FIG. 5;

FIG. 8 is a fragmentary, front elevation view showing a modified form ofthe web severing mechanism of this invention; and

FIG. 9 is a vertical section view taken along lines 99 of FIG. 8.

The packaging machine of which this invention forms a partconventionally includes conveyor means for propelling a continuous webof wrapping material over a forming die so as to shape the web in theform of an elongated tube within which articles fed in by a separateconveyor are enclosed in spaced apart relationship. These preliminarysteps have not been illustrated as they form no part of this invention.The wrapping Web with the entubed articles to be packaged, such as candybars, is then conveyed to a sealing and cutoff station at which the endsof the wrapping material between adjacent articles are sealed togetherand cutoff. A sealing die assembly incorporating the improved cutoffarrangement of my invention is indicated generally by reference numeral1 in FIGS. 1 and 2. The assembly is supported on upright members 2 and 3on which horizontal beams 4 and 5 are supported. Vertical frame members6, 7, 8 and 9 (not shown) extend upwardly from horizontal beams 4 and 5,and transverse bearing blocks 10, 12, 14, and 16 extend therebetween.Upper shaft 18, which is rotatably mounted between bearing blocks and12, supports a first crimping and sealing die 20. A mating crimping andsealing die 24 is fastened to lower, rotary shaft 22 supported betweenbearing blocks 14 and 16.

Rotary motion is imparted to shaft 22 by means of an epicyclic geartrain having a main, eccentric drive gear 24 which is rigidly secured tostub shaft 26. Hub 28 serves to drivingly connect main power input shaft30 to stub shaft 26 in such a manner that stub shaft 26 and input ordrive gear 24 are disposed eccentrically with respect to rotary powershaft 30, thereby causing eccentric gear 24 to move in an orbit as shaft30 rotates. Link 32 is rotatably supported by means of collar 33 onhearing 34 secured to stub shaft 26. The other end of link 32 isrotatably mounted on floating stub shaft 36 by means of bearing 38. Asecond gear 40 having its teeth enmeshed with the teeth of eccentricdrive gear 24 is rotatably supported on floating stub shaft 36. Theteeth of gear 40 are also in driving engagement with the teeth of gear42 which is supported for rotational movement on stub shaft 44. Bearing46 on shaft 44 pivotally supports a second link 49 which is connected atits outer or lower end to bearing 38 on shaft 36. As eccentric drivegear 24 orbits in the clockwise direction indicated by the arrow in FIG.2, the number of its teeth meshing with the teeth on gear 40, and thepoint of mesh, constantly changes; and, therefore, the angular velocityat which gear 40 is driven by gear 24 varies within each revolution ofgear 24. Also, interconnecting link 32 causes gear 40 to oscillate backand forth as gear 24 orbits, and the relative angular disposition oflinks 32 and 49 will change from the acute angle shown in FIG. 2 to anobtuse angle when gear 24 is at the bottom of its orbit. As gear 24orbits downwardly it drives gear 40 at an increasing angular speed dueto the increase in the number of teeth meshing; and, as gear 24 orbitsupwardly it drives gear 40 at a decreasing speed. Since gear 40 isconstantly enmeshed with gear 42, its changing angular velocity will bereflected in a corresponding constant change in the angular velocity ofgear 42. As gear 40 moves to the left, it drives =wear 42 at anincreasing rotational speed because of the change in the point of meshof the teeth of the two gears. Gear 40 will be rotating at an increasingor accelerated angular speed as it moves to the left because eccentricdrive gear 24 is moving downwardly at that time; therefore, the angularspeed of gear 42 will also be accelerating at this time.correspondingly, as gear 40 moves to the right, it will drive gear 42 ata decreasing rotational speed.

The rotation of gear 42 by the aforesaid epicyclic gear train willresult in the rotational movement of lower shaft 22 to which gear 42 isrigidly attached. Pinion gear 48 on shaft 22 will in turn drive enmeshedpinion 50, thereby causing the rotation of upper shaft 18 in acounterclockwise direction. By virtue of the above-described epicyclicgear drive arrangement, shafts 18 and 22 and dies 20 and 24 mountedthereon will rotate at constantly changing angular velocities. Crimpingand sealing dies 20 and 24 are so located on shafts 18 and 22 that theywill be rotating at a maximum speed when they are in the position shownin FIG. 1 directly opposite each other in face-toface engagement withthe wrapping web; and, they will then rotate at a decreasing speed sothat the article to be packaged may pass completely by them before theyagain engage the wrapping web.

As may be noted with respect to FIGS. 1 and 2, upper bearing blocks 10and 12 are free to float or shift vertically and are urged downwardlytowards lower, stationary bearing blocks 14 and 16 by tension springs 52and 53. The purpose of springs 52 and 53- is to maintain the desiredpressure on sealing die heads 20 and 24 so that they will engage thewrapping web with suflicient pressure as it passes between them toproperly carry out the sealing and crimping of the wrapper betweenadjacent articles. The tension force exerted by springs 52 and 53 onfloating bearing blocks 10 and 12 may be adjusted by turning adjustingscrews 54 and 55 which bear against the top of the springs in the mannershown most clearly in FIG. 2. Adjusting screws 54 and 55 are housedwithin externally threaded, tubular members 56 and 57 which may berotated by hand Wheel 58 (FIG. 1) to effect the vertical adjustment ofbearing blocks 10-, 12, 14 and 16 on vertical frame members 6, 7, 8 and9. For this purpose, there is provided a vertically shiftable frameassembly comprised of horizontally extending cross member 60 anddownwardly depending legs, two of which are shown at 61 and 62 in FIG.2. Cross member 60 is notched at its opposite ends to receive the inneredges of upright frame supports 6, 7, 8 and 9 along which the frameassembly comprised of cross member 60 and the downwardly depending legs61 and 62 may slide up and down. Tubular adjusting stems 56 and 57extend downwardly through cross member 60 in threaded engagementtherewith. Sprockets 63 and 64 are mounted on adjusting stems 56 and 57for rotation therewith, rotary movement being transmitted from sprocket63 to sprocket 64 by interconnecting chain 65. Bearing blocks 10, 12, 14and 16 may be releasably secured to the frame assembly legs 61, 62, etseq. by fastening means (not shown) to permit the vertical adjustment ofthe bearing blocks together as a unitary assembly. This may beaccomplished by turning hand wheel 58, which is firmly attached to theupper end of adjusting stem 57. The rotation of hand wheel 58 willrevolve adjusting stem 57, which will in turn transmit rotary power toadjusting stem 56 by means of sprockets 63 and 64 and connecting chain65. As adjusting stems 56 and 57 rotate, the bearing block adjustingassembly 60, 61, 62 will be displaced vertically by reason of thethreaded attachment of cross member 66 to threaded stems 56 and 57.Thus, depending upon the direction of rotation of hand wheel 58, hearingblocks 10', 12, 14 and 16 will be carried upwardly or downwardly ralongupright frame supports 6, 7, 8 and 9 by frame assembly 60, 61, 62.

Upper, floating bearing blocks 10 and 12 may also be adjusted verticallyrelative to lower bearing blocks 14 and 16 by a threaded stud andadjusting nut arrangement which appears most clearly in FIG. 6. Stud 66extends between bearing blocks 10 and 14 and is seated in recessestherein, the upper end of stud 66 being secured to hearing block 10 toprevent the rotation of stud 66 as nut 68 is turned. Stud 66 isshiftable vertically within a recess in the top of lower bearing block14. By rotating nut 68 either clockwise or counterclockwise stud 66twill be made to move up or down so as to thereby cause floating bearingblock 10 to move towards or away from lower, stationary bearing block14. This adjustment means may be utilized to precisely fix the spacingbetween crimping and sealing dies '20 and 24 for a particular wrappingweb thickness.

As the wrapping web containing entubed articles passes between sealingand cut-off die heads 20 and 24, the opposite faces of the wrapping web7!} are crimped together and sealed between adjacent packaged articlesby the rotation of sealing heads 20 and 24 into contact therewith in themanner indicated in FIG. 3. Ordinarily, it is necessary to cut wrappingweb 70 between adjacent articles so that the ends of the separatepackages may then be tucked and sealed against each package in asubsequent operation. For the purpose of carrying out this web-cuttingoperation, I have provided a unique arrangement utilizing an elongatedcutoff knife 72. Referring now to FIGS. 1, 3 and 4, it will be seen thatknife 72 is mounted transversely with respect to the path of movement ofwrapping web 70 and is housed within a long, narrow slot 74 in uppersealing die 20'. Knife 72 is movably supported for reciprocal movementin and out of slot 74 by links 76 and 78 which are pivotally secured tothe opposite ends of die head within recess 80. A coil spring 82 actingagainst collar 84 of knife handle 86 serves to bias operating links 76and 78 towards the rest position shown in FIG. 1 wherein they hold knife72 in its normal, retracted position within slot or recess 74 of diehead 20. It is to be noted that in its rest position knife 72 is held inits entirety within slot or recess 74 so that its cutting edge does notproject outwardly beyond the peripheral surface of sealing die 20. Thisarrangement insures that knife 72 will not interfere with the pressurecontact between sealing and crimping dies 20 and 24, and is alsoimportant with respect to the proper carrying out of strip packagingoperations hereinafter described. Knife operating links 76 and 78 arearranged to be pivoted in such a way as to carry knife 72 downwardly andlaterally out of slot 74 through and across wrapping web 70. Acomplementary slot 88 is provided in the upper base of lower sealing die24 to receive knife 72 as it passes downwardly through wrapping web 70.In addition to links 76 and 78, the operating mechanism for knife 72includes a cam follower roller 90 attached to link 76. In order thatknife 72 may be smoothly received into slot 88 in lower die head 24without interfering with the sealing and crimping of the 'wrapping webmoving between the two die heads, it is essential that the knifeoperating mechanism be actuated when die heads 20 and 24 have rotatedinto direct vertical alignment with each other in pressure contact withthe opposite faces of wrapping web 70. In FIGS. 1 and 3, I have shown apreferred form of trip means for actuating the knife-operat ingmechanism comprising a stationary strike member 92 secured to a threadedpin 94. A lock nut 96 holds threaded pin 94 to mounting plate 98 whichis attached to upper, floating bearing block 10. As may be noted mostclearly with respect to FIG. 3, strike member 92 has a substantiallyoval configuration with triangular projections, the upper one of whichis adapted to strike cam roller 90 as sealing dies 20 and 24 rotatetoward each other. The direction of rotation of shafts 18 and 22 isindicated by directional arrows in FIG. 3. Strike member 92 is oifsetslightly with respect to the vertically aligned position of dies heads20 and 24 and is vertically oriented so that its upper, triangularprojection 93 will contact cam roller 90 to actuate knife operatinglinks 76 and 78 just before crimping and sealing heads 20 and 24 are indirect vertical alignment. In the instant that it takes for knife 72 tobe fully displaced downwardly out of slot 74, sealing heads 20 and 24will have rotated into vertical alignment in the position shown in FIG.3 wherein they will crimp and seal wrapping web 70 therebetween. Whencam roller 90 strikes projection 93 of strike member 94, it will bedisplaced upwardly, thereby causing link 76 to pivot to the phantom lineposition shown in FIG. 1. As link 76 pivots downwardly, it will pullknife 72 downwardly and laterally out of slot 74 against the pressure ofspring 82. The movement of knife 72 out of slot 74 will cause link 78 topivot to the vertical, phantom line position shown in FIG. 1. Thetriangular shape of projection 93 of strike member 92 insures that camroller 90 will not dwell at the upper limit of its displacement path andwill immediately return downwardly to its normal position of rest as itrotates past strike member 92 with die head 20. This very quick upwardand downward movement of cam roller 90 insures that knife 72 willpenetrate very rapidly through wrapping web 70 with a sharp, swiftguillotine-type of cutting stroke which cleanly severs wrapping 70without interfering with the sealing action between dies 20 and 24.After cam roller 90 passes strike member 92 spring 82 returns knife 72to its position of rest within upper slot 74. The angular disposition ofstrike member 92 is so selected that knife 72 will be actuated at theprecise instant when sealing dies 20 and 24 are directly opposite eachother in sealing engagement with opposite faces of web 70. Theinitiation of the knife cutting action in this manner provides severaladvantages. First of all, it insures the positioning of knife 72 andcomplementary receiving slot 88 directly opposite each other so that asknife 72 penetrates through wrapping web 70, it will be cleanly receivedwithin slot 88 in lower sealing die 24. Also, the cutting action ofknife 72 is improved by causing it to move through web 70 at the instantthat the web is held tightly between sealing dies 20 and 24.

Knife 72 is preferably provided with a sharp, scalloped bottom edge toenhance its cutting action. Also, knife 72 and receiving slot 88 are sooriented on their respective sealing dies 20 and 24 that as knife 70moves downwardly :into slot 88 it will slide over back wall 89 thereofso as to provide a desirable shearing action. This disposition of knife72 with respect to receiving slot 88 is best shown in FIG. 3.

It is noteworthy that there is a particular advantage derived frommounting knife trip member 92 on upper, floating bearing block 10. Iftrip member were mounted on upright frame support 6 or otherwise notattached to one of the floating bearing blocks 10 or 12, the upwardforce exerted on roller 90 by strike member 94 could cause upper shaft18 and its floating bearing blocks 10 and 12 to shift upwardly a slightdistance against tension springs 52 and 53, thereby undesirably reducingthe crimping and sealing pressure with which die head 20 contacts lowerdie head 24 and wrapping web 70 passing therebetween. Since strikemember 92 is mounted on floating bearing block 10, there can be norelative vertical movement therebetween as roller 90 strikes member 92.Thus, shaft 18 and upper die head 20 will not be displaced upwardly andthe desired sealing pressure of the die heads 20 and 24 is maintained.

Provision has been made for the vertical and horizontal adjustment ofstrike member 92 to permit control of the depth of knife penetration aswell as the initial point of knife activation. As may be noted withrespect to FIGS. 1 and 2, strike member mounting plate 98 abuts againstthe lower face of bearing block 10 and is attached thereto by fasteners100. Fasteners 100 extend through horizontal slots 102 in mounting plate98, whereby plate 98 may be shifted laterally to horizontally adjuststrike member 92 by loosening fasteners 100. Vertical adjustment ofstrike member 92 is accomplished by loosening nut 96 and moving carrierpin 94 upwardly or downwardly in a vertical slot (not shown) in mountingplate 98 within which pin 94 is received.

In FIGS. 5, 6 and 7, I have shown a knife-actuating arrangement designedto effect cutoffs of multiple lengths of packages in a strip packagingoperation. In such an operation groups of packages containing somepredetermined number of packaged articles such as 6, 10 or 12 would becut off into strips comprising a continuous length of wrapping webconnecting the several packaged articles together. Strip packaging thusrequires that the web cutofi knife be controlled in such a way as topermit a predetermined number of packaged articles to pass between thecrimping and sealing dies to effect the sealing of the wrapping webbetween adjacent articles without severing the web. My improvedguillotine-type of cutoff knife uti lizing a reciprocal knife 72contained within a slot in one of the rotary sealing dies isparticularly well suited for a strip packaging operation. Since knife 72is entirely contained within slot 74 in upper sealing die 20 and doesnot project outwardly beyond the peripheral surface of sealing head 20,the moving wrapping web may be sealed a plurality of times between apredetermined number of packaged articles by rotating sealing andcrimping dies 20 and 24 without severing web 70 or interfering with thesealing operation in any way as long as knife 72 is not tripped. Inorder to control the actuation of knife 72 at predetermined intervals, Ihave mounted knife trip member 92 on reciprocating piston 104 of adouble-acting pneumatic cylinder 106. Strike member 92 is of the sameconfiguration as that shown in FIGS. 1 and 3 and is secured to the outerend of piston 104 by a right angle elbow 108 in order that it mayproject into the orbital path of roller element 90 of theknife-operating mechanism. Pneumatic cylinder 106 is mounted byfasteners 110 to a plate 112 which is secured to the lower end offloating bearing block in a manner similar to that in which mountingplate 98 of FIGS. 1 and 2 is attached to bearing block 10. Air lines 113and 114 attached to opposite ends of pneumatic cylinder 106 areconnected to a solenoid valve 116 which controls the flow of air from amain supply line 118 connected to a pressurized air source (not shown).Solenoid valve 116 is intermittently energized to direct pressurized airthrough either line 113 or line 114 to alternately extend and retractpneumatic piston 104. The intermittent actuation of solenoid valve 116may be accomplished by a signal from various control devices such as acounter or micro switch responsive to the passage of a predeterminednumber of entubed articles past sealing and crimping dies and 24. Forillustrative purposes, I have shown a counter 120 to which electricallead lines 117 from solenoid valve 116 are connected. Counter 120 isprovided with a conventional sensor or feeler device (not shown) bymeans of which it may signal the passage of a predetermined number ofarticles past the crimping and sealing station. Thus, counter 120 willbe set to complete an electrical circuit to solenoid valve 116 after thedesired number, such as 6, 8 or 10, of wrapped articles has passedbetween die heads 20 and 24. In its de-energized position solenoid valve116 will direct pressurized air through line 114 so as to hold piston104 in its retracted position. With piston 104 withdrawn or retracted,strike member 92 will be held in a position in which it is removed fromthe rotary path of knifeoperating roller 90. Sealing dies 20' and 24will pass through a predetermined number of revolutions to accomplishthe crimping and sealing of wrapping web 70 between entubed articles;and since roller 90 will not be contacted by strike member 92, knife 72will not be actuated. Thus, wrapping web 70 will not be severed, and astrip of packaged articles connected by a continuous length of wrappingweb will pass through the sealing and crimping station. Since knife 72is completely withdrawn within slot 74 of upper die head 20 by spring 82and does not project outwardly beyond the peripheral surface of sealingdie 20, it will not strike, indent or sever the wrapping web 70 orinterfere in any way with the sealing of wrapping web 70 a preselectednumber of times by rotating dies 20 and 24. The passage of the desirednumber of wrapped articles past die heads 20 and 24 will be signalled bycounter 120 to accomplish the actuation of solenoid valve 116. Whenthree-way valve 116 is energized, it will shut off the flow of airthrough line 114 and direct pressurized air from supply line 118 intoline 113 to thereby extend pneumatic piston 104 to the position shown inFIG. 6. When fully extended, piston 104 will hold strike member 92 inposition to contact revolving roller '90. When roller 90 contacts strikemember 92, it will be cammed upwardly, whereby link 76 will pivot topull knife 72 downwardly and laterally in a guillotine-like cuttingmotion through wrapping web 70 in the manner described above withrespect to FIGS. 1 through 4. In FIG. 5, roller element 90 is shown inits upwardly displaced position wherein it has pivoted link 76downwardly and thus completed the downward cutting motion of knife 72.Knife 72 is shown at the bottom of its cutting stroke in engagement withreceiving slot 88 in lower die head 24 in FIGS. 5 and 7. After knife 72has severed wrapping web 70, solenoid valve 116 will automatically bede-energized to thereby cause pneumatic cylinder 106 to retract piston104 and move strike member 92 to its inoperative position. The strippackaging cycle will then be repeated with another group of wrappedarticles passing between die heads 20 and 24 for sealing of the wrappingweb 70 before pneumatic piston 104 is again actuated to bring strikemember 92 into position to trip knife 72 and again sever wrapping web70'.

-In FIGS. 8 and 9, I have shown an alternative form of knife trip meanscomprising a cam holder 120 and trip cam 122. Cam holder 120 is fastenedto lower, rotary shaft 22 for rotational movement therewith, and tripcam 122 thus revolves with shaft 22 and lower die head 24. As mayreadily be understood by reference to FIGS. 8 and 9, cam 122 willperiodically strike roller or cam follower as cam holder rotates withshaft 22, thereby displacing cam follower 90 upwardly and causing link76 to pivot to the phantom line position shown in FIG. 8. As link 76pivots downwardly, it will pull knife 72 laterally across web 70 as wellas downwardly therethrough in the manner described above with respect tothe actuating arrangement of FIGS. 1 through 4. As knife 72 severswrapping web 70, it will pass into receiving slot 88 in lower sealingdie 24. The angular disposition of cam 122 on cam holder 120 is selectedso that cam 122 will strike cam follower 90 and actuate knife 72 so asto sever web 70 at the precise instant that sealing dies 20 and 24 aredirectly opposite each other in sealing engagement with the oppositefaces of web 70. Since cam 122 will engage roller or cam follower 90 assealing dies 20 and 24 reach their maximum rotational speed for sealingengagement with moving web 70, cam 122 will also be rotating at arelatively high angular velocity, thereby bringing about the very rapidcutting action and subsequent retraction of knife 72. Thus, therevolving cam-type trip arrangement of FIGS. 8 and 9, like thestationary strike member 92 of FIGS. 1 through 4, provides a clean,swift severing of wrapping web 70 Without interfering with the sealingaction of dies 20 and 24.

Those skilled in the packaging machinery art will readily appreciatethat the penetrating, guillotine-like cutting action of knife 72represents a distinct improvement over the pressure type of rotarycutting dies heretofore available. Not only does guillotine cutoff knife72 provide a better cutting action, but also it insures improved seailngof the wrapping web by eliminating outwardly projecting cutoff dieswhich tend to hold the sealing and crimping dies apart. Knife 72 is alsorelatively simple and economical to replace, and its adjustment withinupper sealing die 20 is not critical. The depth of knife penetrationthrough the wrapping web is accurately controlled by properly adjustingtrip member 92 or 122. Rotary cutoff dies of the anvil type shown in US.Pat. No. 2,546,721 require constant adjusting because of the wear causedby the knife die striking the mating, anvil die. As the rotary,anvil-type cutoff dies are adjusted outwardly to compensate for Wear,they interfere more and more with the simultaneous pressure sealing ofthe rotary sealing dies to which they are secured.

It is to be noted that the gear train utilized to rotate shafts 18 and22 may be employed to operate knife 72 through some mechanism other thanrotary trip cam 122. The primary consideration is that the cuttingstroke of knife 72 be coordinated with the angular disposition of rotarysealing dies 20 and 24 so that the severing of web 70 takes place whenthe sealing dies are in the proper position of alignment with each otherso that knife 72 may pass cleanly into receiving slot 88 on die head 24.For purposes of my invention, the particular manner employed for sealingthe opposite faces of wrapping web 70 together between adjacent entubedarticles is of no particular significance. An adhesive material may beemployed to seal the wrapper web as it is pressed between the oppositelydisposed faces of sealing dies 20 and 24, or the well-known heat sealingmethod may be utilized. The wrapper engaging faces of the dies may beknurled or roughened so as to permit them to crimp the Wrapper at thesame time that it is sealed. However, for purposes of this invention, itis immaterial Whether the wrapping web is crimped as well as sealed.

to thereby effect the actuation of said operating mechanism. 4.Packaging apparatus as defined in claim 1 wherein: said trip meanscomprises a strike member movable 5 between a first position in which itis operative to What is claimed is:

1. In a packaging machine having a station at which a moving, formedwrapping web enclosing spaced-apart articles is sealed and cut offbetween adjacent articles, the improvement comprising:

a pair of oppositely disposed sealing dies directly mounted on separate,rotary shafts disposed parallel to each other in spaced apart relation,said sealing dies being rotatable with said rotary shafts througharcuate paths wherein said sealing dies intermittently strike andactuate and knife operating mechanism and a second position in which itis removed from the rotary path of said knife-operating mechanism; and

control means operative to move said strike member come into directalignment with each other and en- 10 from said second position to saidfirst position in gage said wrapping web therebetween at only oneresponse to the movement of a predetermined numpoint in said arcuatepaths during each revolution of her of articles past said sealing dies.

said rotary shafts; 5. Packaging apparatus as defined in claim 4wherein: drive means for imparting rotational movement to said saidcontrol means includes a fluid motor operatively rotary shafts andsealing dies;

a recess within one of said sealing dies;

a movable cutting knife housed within said recess and held therein in anormal position wherein its cutting edge does not project outwardlybeyond the peripheral, web engaging surface of said one sealing die;

an operating mechanism connected to said knife and operable to move saidknife relative to said one of said sealing dies, out of said recess andthrough said associated with said strike member for moving said strikemember between said first and second positions. 6. In a packagingmachine having oppositely disposed 2Q sealing dies arranged tointermittently engage therebetween a continuous length of wrapping webbetween spaced apart articles entu'bed therein, the improvementcomprising:

first and second rotary shafts disposed parallel to each Wrapping webina cutting motion; other in spaced-apart relation, said first shaftbeing an opening ithi th th one f id sealing die rotatably supported atits opposite ends in floating constructed and arranged to receive saidknife as it aring blocks;

cuts through said wrapping web; and a first sealing die mounted on saidfirst rotary shaft and trip means located in the arcuate path of saidone sealhaving a recess therein within which a cut-off knife ing die andso constructed and arranged as to is movably supported.

immediately contact and actuate said operating mecha Second sealing diemounted on said second rotary anism so as to fully extend said knifethrough its shaft nd ng n pening h r in a apted to refull cutting motionat the instant when said sealing ceive d knife when it cuts through Saidpp dies are rotated to a position in direct alignment with each other,said trip means being further adapted to spring means urging saidfloating bearing blocks and quickly rglease said operating mechanism assaid said first rotary shaft towards said SGCOI'ld rotary sealing diesrotate past said aligned position, whereby Shaft in Order to maintainthe P p Pressure 011 said knife is actuated and released in rapidsuccession i Sealing dieshs y are rotated into engagement to provide asharp, quick cutting action during the Wlth i PP W613;

very short i i l h id opening i hi h $0 an operating mechanism connectedto said knife and other one of i li di i i alignment i h operable tomove said knife out of said recess and Said knife through said wrappingweb as said web moves be- 2. Packaging apparatus as defined in claim 1,wherein: 5 said Sealing dies; and said knife is in the form of anelongated blade disposed 11 mp fnember p d on one of a sprmg-loadedtransversely of the path of travel of said wrapping bearing blocks, sa1dtrip member belng so positioned web; as to contact a portion of saidknife operating mechspring means biases said knife in said normalposition ahism and thereby initiate the cutting movement of within Saidrecess; and sa1d knife when sa1d sealing dies are rotated to a saidoperating mechanism includes pivotal linkage ele- Position in fhfectalignment W each o er in enments connected to said knife and operativeto overgagemeht Wlth the PP sldes of 1 pp come the pressure of saidspring means and move said knife through said wrapping web in responseReferences Cited to actuation by said trip means, said linkage ele-UNITED STATES PATENTS ments being pivotally arranged in such a way as to55 2,960,808 11/1960 Pike I X carry sa1d knife out of sa1d recess alongan angular 2,966,021 12/1960 Lane et a1 path wherein said knife movestransversely with respect to said web as it cuts thereth'rough. 3.Packaging apparatus as defined in claim 1 wherein:

said trip means comprises a cam carried on the same FOREIGN PATENTS102,740 10/1962 Netherlands.

THERON E. CONDON, Primary Examiner E. F. DESMOND, Assistant Examiner US.Cl. X.R. 53-167 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 3 524 301 Dated August 18 1970 Inventofls) Darwin DuaneZimmerman It is certified that error appears in the aboveidentifiedpatent and that said Letters Patent are hereby corrected as shown below:

In claim 4, line 4, change "and" before "knife" to --saiu---- SIGNED M-FWLEifi Atteat:

Edward M. Fletcher, Jr

Attcsting Officer WILLIAM E. SGHUYIIER, JR-

Gomiasiom of Patents FORM P0-1050(10-69) USCOMM DC 376 p6 n u s eovnuuzmnmmnc orrlc: "u o-sn-ne

